The present invention relates to a method for manufacturing shock absorbing materials using wastepaper, and particularly to a manufacturing method for wastepaper shock absorbing materials using vacuum forming principle and wastepaper shock absorbing materials using the method. More particularly, the present invention relates to a method for manufacturing shock absorbing materials by vacuum-dehydrating pulp suspension mixed with cationic starch to a dual direction using a vacuum former capable of dual vacuuming process.
Typical shock absorbing (cushion) materials currently on the market include, but not limited to, Styrofoam, pulp mold, polypropylene and polyethylene. All these materials, excluding the pulp mold, have come to be regarded as non-degradable (water-non-dispersible, water-non-soluble, and/or water-non-biogradable) packing materials that hardly solve in the natural environment. The Styrofoam is called in various names such as foam polystyrene, Styrofoam, expanded styrene, Styropor and the like. The Styropor is a trademark of a German chemical conglomerate BASF AG., and the Styrofoam is an insulating material trademark of Dow Chemical of USA, which is widely known as Styropor in Korea. The Styrofoam is a product manufactured by infusing hydrocarbon gas such as pentane or butane into polystyrene resin, which is then blown or expanded by vapor. The Styrofoam is a natural resource-conserving material mainly composed of air (98%) and resin (2%) as remainder.
Due to widespread environmental concerns and drawbacks that the aforementioned non-degradable packing materials are made from fossil raw materials, and difficult to solve in natural conditions, movements have strongly arisen in developed countries to discontinue use of and prohibit Styrofoam. Problem awareness of environmental pollution caused by packing materials has exerted a direct influence on environmental restriction in respective countries and on international trades as well.
The European Union (EU) promulgated a “packages and packaging wastes directive” for promoting reduction and recycling of packaging wastes, whereby member states are required to collect 50-60% and recycle 25-45% of packaging wastes, and to reduce minimum 15% of reusable products per material by 2001. A directive under implementation requires the member states to prohibit use of materials containing environmentally hazardous substances including Hg and Pb in relation to export packages for electric home appliances, remove and reuse 50% of a gross weight of generated packaging wastes, and to recycle 25% or more.
Such developed countries including the USA, Swiss, Sweden and Italy restrict use of Styrofoam containers and PVC packing materials, and Germany, France and Sweden have started to implement a compliance with so-called “Extended Producer Responsibility” environmental regulations in which manufacturers, distributors and importers are responsible for removing packing materials after consumption thereof. Particularly, a packaging regulation in Germany requires manufacturers or retailers to present a removal target for each period over three stages including transportation packages, secondary packages and sales packages. The regulation has achieved a remarkable result in reducing or curbing use of environmentally hazardous materials. The first stage has made it a duty for the manufacturers and sellers to remove transportation packages, and the second stage calls for retailers to remove secondary packages additionally wrapped on merchandise wrappings for advertisement or theft prevention purpose. At this time, retailers are requested to install a collection box near retailer shops. The third and last stage requires retailer shops to collect or remove merchandise wrappings at sales points. As the regulations are beefed up against using hardly-soluble packing materials, demands for environment-friendly packing materials are expected to increase rapidly, such that it is anticipated that demands for shock absorbing materials made of wastepaper fibers will increase at a great speed.
Recently, shock absorbing materials manufactured by using wastepaper fibers are produced in the name of pulp mold, and used as substitutes for packaging Styrofoam.
Referring to FIG. 1, the pulp mold was first used for egg cases, and thereafter widely used for industrial and consumer product wrappings. A pulp mold manufactured by a pulp mold manufacturing apparatus (FIG. 2) may be a pulp molded goods (articles) made by pouring wastepaper suspension into a forming box, and an excessive amount of water contained in the suspension being pressed, vacuum-dehydrated to one direction and dried.
The pulp mold itself thus manufactured, being composed of very dense fibrous structure (FIG. 3), has no shock absorbing ability, such that the pulp mold is provided by a separate mold with a free space to enable to prevent external shock (impact) or vibration from being directly transmitted thereto.
Another drawback is that the shock absorbing ability can hardly be retained unless moisture contents of shock absorbing materials are kept at a predetermined level or more because of characteristic of manufacturing method thereof in which wastepaper fibers are blown or expanded, and starch used as expanding supplementary agents.